This exercise in moral equivalence is unconvincing, if not dishonest. Would Obama be friendly with someone who actually bombed abortion clinics and defends that conduct? Not likely. But he is friendly with William Ayers, a leader of the radical Weather Underground, which in the 1970s carried out numerous bombings, including one inside the U.S. Capitol. (Though the last person who should object is Hillary Clinton, whose husband pardoned two Weather Underground members.)

Obama minimized his relationship by acknowledging only that he knows Ayers. But they have quite a bit more of a connection than that. He's appeared on panels with Ayers, served on a foundation board with him and held a 1995 campaign event at the home of Ayers and his wife, fellow former terrorist Bernardine Dohrn. Ayers even gave money to one of his campaigns.

It's not as though Ayers and Dohrn have denied or repudiated their crimes. After emerging from years in hiding, they escaped federal prosecution because of government misconduct in gathering evidence, but they don't pretend they were innocent. In 2001, Ayers said, "I don't regret setting bombs. I feel we didn't do enough."